Brain food

Carbohydrate gels aren’t just for your legs – the brain runs almost exclusively on glucose. ‘The brain is very sensitive to decreases in blood glucose concentration,’ says Martin Sellens, professor of sports and exercise science at the University of Essex. ‘It might even cause the body to slow mid-run to protect its supply.’ Backing this, recent University of Birmingham research found that 60-minute time trial performance improved when athletes swished a sports drink and spat it out. The researchers reckon sensors in the athletes’ mouths sent signals to the brain announcing the impending fuel. The brain then allowed the body to go faster in anticipation.

HOW

While your muscles don’t need extra carbohydrate on runs of less than 90 minutes, your brain may benefit from regularly swilling sports drink during 45-75-minute runs. ‘Mouth-rinsing with a shot of a 6.4 per cent maltodextrin [a complex carb] solution seems to work,’ says Sellens. ‘This is a similar concentration to most sports drinks, suggesting that just the promise of glucose is enough to convince the brain to maintain intensity.’ It also pays to keep your glycogen stores stocked by eating low glycaemic index (GI) foods such as sweet potatoes, porridge, brown rice and broccoli. ‘Low GI foods release energy slowly into the bloodstream,’ says Shona Wilkinson, head nutritionist at The Nutri Centre. ‘This ensures a steady flow of energy to the brain.’

Runner's World is a publication of Hearst Magazines UK which is the trading name of The National Magazine Company Ltd, 72 Broadwick Street, London, W1F 9EP. Registered in England 112955. All rights reserved. Runner's World, Part of the Hearst UK wellbeing network